We get more colds in winter than summer--not because it’s colder or wetter, but because we spend more time indoors where viruses are easier to swap. Classroom-cloistered children prove to be expert carriers of the malady.

Cold sufferers are infectious a day or two before they experience symptoms. Sinus congestion and colored nasal discharge are common signs of a cold, not necessarily the result of a bacterial infection, so antibiotics aren’t needed. Colds can last up to 14 days, and coughs can linger longer.

The best preventive action? Wash your hands often, and keep your immune system strong by eating plenty of fruits and vegetables.